/**
 * javascript只支持单继承，不支持多继承
 * Bird想同时继承Animal和Flyer
 *
 * class Animal{
 *   running(){}
 * }
 *
 * class Flyer{
 *   flying(){}
 * }
 *
 * class Bird {}
 *
 *
 * */


class A {
  methodA() {
    console.log("Method A from class A");
  }
}

class B {
  methodB() {
    console.log("Method B from class B");
  }
}

class C {
  methodC() {
    console.log("Method C from class C");
  }
}


class D {
  methodD() {
    console.log("Method D from class D");
  }
}



